1. Field of the Invention
This application relates to the field of computer data storage and more particularly to the field of configuring control system call access to data storage devices.
2. Description of Related Art
Host systems may store and retrieve data using a data storage device containing a plurality of host interface units (ports) that communicate with and store and retrieve data on internal storage facilities provided within the data storage device. Such data storage devices are provided, for example, by EMC Corporation of Hopkinton, Mass. and disclosed in U.S. Pat. No. 5,206,939 to Yanai et al., U.S. Pat. No. 5,778,394 to Galtzur et al., U.S. Pat. No. 5,845,147 to Vishlitzky et al., and U.S. Pat. No. 5,857,208 to Ofek.
The host systems may be assigned limited access to specific portions of the internal storage facilities, where that access may include reading and writing data and “system calls” that cause the data storage device to execute administrative-like operations (e.g., automatic mirroring, copying, back up). The system calls do not directly read and write data; However even so, system calls may cause one of the user host systems to indirectly access data allocated to another one of the host systems. In addition, remote system calls may be issued to a storage element through a remote storage device (e.g., in a disaster recovery situation) or through a fabric port.
The use of system calls which may provide one host system with unintended indirect access to a memory resource allocated to another host system may not be a problem if all host systems and the entire storage device are controlled by a single entity (i.e., are all owned and operated by a single company) that is capable of coordinating access among different groups within the entity. However, in instances where not all of the host systems are controlled by a single entity (e.g., in instances where a plurality of different smaller companies share use of a single data storage device) and in instances where different groups of the same entity access the host systems in an uncoordinated manner, it may be undesirable to allow such indirect access of internal storage facilities using system calls, especially in instances where the data storage device contains sensitive data of one or more of the entities and/or groups within a single entity. Furthermore, in configurations where a storage device is coupled to additional storage devices to provide backup services therefor, it may be undesirable to allow unintended access to data via system, calls.